KINSHASA, Feb 10 (Reuters) - Copper production in Democratic Republic of Congo dropped for the first time in six years in 2015 and this year could be another tough one as low commodity prices bite, the Central African country’s chamber of mines said on Wednesday.

Output dropped 3.3 percent in Africa’s top copper producer to 995,805 tonnes from 1.03 million tonnes in 2014, the first time production fell since the global economic downturn in 2009.

The sharpest fall was in the fourth quarter when production slumped 12 percent year-on-year, in part due to the suspension of some production at miner and trader Glencore’s Katanga Mining unit, the industry group said in its annual report.

The mine, one of the largest in Congo, producing 113,674 tonnes of copper in the first nine months of 2015, is not expected to reopen until mid-2017.

Mines Minister Martin Kabwelulu told a conference in Cape Town on Wednesday that 2015 copper production rose nearly 4 percent to 1.069 million tonnes. There was no immediate explanation for the discrepancy.

Congo’s economy is highly dependent on the mining sector, which accounts for about 20 percent of GDP. Copper and cobalt alone accounted for 79 percent of the country’s exports in the first half of 2015, according to the Central Bank.

Benchmark copper fell 25 percent last year, a slump that the chamber said could continue. Indeed, copper prices are expected to hit their lowest average in more than a decade this year as global supply outruns demand, a Reuters survey of metal analysts showed last month.

The government scaled back its 2015 growth estimate to 7.7 percent from over 10 percent because of low metals prices. It has said Katanga Mining’s 18-month suspension will cost it more than $200 million in tax revenues this year.

The government expects growth to rebound to 9 percent this year while the International Monetary Fund (IMF) predicts 7.3 percent growth.

The country’s copper-producing southeast only receives about half the electricity it needs. The government is backing a series of projects to boost supply but the chamber said “inadequate and highly non-transparent management” of the sector led to “little progress” in 2015.

The chamber’s report, however, cited causes for optimism, noting that new mines started commercial production in 2015 and several major projects that are expected to come online in the coming years.

Ivanhoe Mines’ Kamoa project, slated to begin production in 2018, is thought to be the world’s largest untouched high-grade copper discovery.

In the same report, the chamber of mines said gold production rose 30 percent to an estimated 25,516 kg, partly because of stronger-than-expected production at Randgold Resources’ Kibali mine. Congo’s industrial gold production stood at near zero in 2011.

Production is likely to rise further as Randgold, AngloGold Ashanti and Banro Corporation continue to ramp up output at large mines they have opened in the last five years. (Editing by Matthew Mpoke Bigg and Alexander Smith)